From: "John W. Linville" <[EMAIL PROTECTED]> Date: Thu, 28 Jul 2005 15:47:02 -0400
> On Thu, Jul 28, 2005 at 12:38:53PM -0700, David S. Miller wrote: > > Probably it is better to define the ethtool object returned to the > > user as some kind of TLV, so the size doesn't matter. > > Can you point Jon at a good example of this? Netlink uses this kind of thing a lot, but not too much ethtool stuff does. But something like: struct ethtool_perm_addr { unsigned int cmd; int size; char data[0]; }; and the user says how large his buffer is in the request, and if that is not large enough you return -ETOOBIG or some similarly discernable error code so that userspace can allocate a larger buffer. In fact, the kernel can rewrite the "size" field in this case to indicate how large the buffer needs to be to hold the full address. - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html